Use /tmp dir to store temporary index

[mangalaman93]

Fixes #4600
While running dgraph as systemd service, we may not have permissions to create a folder in the current directory. Now, we instead use /tmp dir to store the temporary index solving the permission denied error.

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[martinmr]

Reviewed 1 of 1 files at r1.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @mangalaman93 and @manishrjain)

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posting/index.go, line 515 at r1 (raw file):

	// directory after the indexing step is complete. This deletes any other temp
	// indexes that may have been left around in case defer wasn't executed.
	tmpParentDir := filepath.Join(os.TempDir(), "dgraph_index")

Consider using https://golang.org/pkg/io/ioutil/#TempDir to avoid issues if multiple are going on or the temp folder is not properly deleted.

[mangalaman93]

Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @manishrjain and @martinmr)

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posting/index.go, line 515 at r1 (raw file):

Previously, martinmr (Martin Martinez Rivera) wrote…

Consider using https://golang.org/pkg/io/ioutil/#TempDir to avoid issues if multiple are going on or the temp folder is not properly deleted.

That is what we are using if you see below. Just keeping everything in one folder though so that if we are looking for the directory for debugging or something, it would be easier to find.

[manishrjain]

Reviewed 1 of 1 files at r1.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @martinmr)

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posting/index.go, line 515 at r1 (raw file):

Previously, mangalaman93 (Aman Mangal) wrote…

That is what we are using if you see below. Just keeping everything in one folder though so that if we are looking for the directory for debugging or something, it would be easier to find.

Add a TODO here: If we get a complaint, we could move this to a flag, so a user can specify what the tmp dir should be.

[mangalaman93]

Reviewable status: 0 of 1 files reviewed, 1 unresolved discussion (waiting on @manishrjain and @martinmr)

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posting/index.go, line 515 at r1 (raw file):

Previously, manishrjain (Manish R Jain) wrote…

Add a TODO here: If we get a complaint, we could move this to a flag, so a user can specify what the tmp dir should be.

Done.